Screening magnetic resonance imaging recommendations and outcomes in patients at high risk for breast cancer

Impact of COVID-19 and Socioeconomic Factors on Delays in High-Risk MRI Breast Cancer Screening

The purpose of this study is to investigate if there was a delay in high-risk MRI breast cancer screening in our local region, if this delay is ongoing despite COVID-19 vaccinations, and if demographic and socioeconomic factors are associated with these delays. Six-hundred and sixty-five high-risk breast patients from 23 January 2018–30 September 2021 were included. Delays were determined by comparing the time in between each patients’ MRI screening exams prior to the COVID-19 pandemic to the time in between MRI screening exams during the height of the COVID-19 pandemic as well as the time in between exams when our patients started receiving vaccinations. Delays were analyzed via logistical regression with demographic and socioeconomic factors to determine if there was an association between these factors and delays. Significant time delays in between MRI screening exams were found between the pre-COVID timeframe compared to during the height of COVID. Significant time delays also persisted during the timeframe after patients started getting vaccinations. There were no associations with delays and socioeconomic or demographic factors. Significant time delays were found in between MRI high-risk breast cancer screening examinations due to the COVID-19 pandemic. These delays were not exacerbated by demographic or socioeconomic factors.

Cone-Beam Breast Computed Tomography: Time for a New Paradigm in Breast Imaging

It is time to reconsider how we image the breast. Although the breast is a 3D structure, we have traditionally used 2D mammography to perform screening and diagnostic imaging. Mammography has been continuously modified and improved, most recently with tomosynthesis and contrast mammography, but it is still using modifications of compression 2D mammography. It is time to consider 3D imaging for this 3D structure. Cone-beam breast computed tomography (CBBCT) is a revolutionary modality that will assist in overcoming the limitations of current imaging for dense breast tissue and overlapping structures. It also allows easy administration of contrast material for functional imaging. With a radiation dose on par with diagnostic mammography, rapid 10 s acquisition, no breast compression, and true high-resolution isotropic imaging, CBBCT has the potential to usher in a new era in breast imaging. These advantages could translate into lower morbidity and mortality from breast cancer.

Abnormal screens among nonmutation carriers in the High Risk Ontario Breast Screening Program

BACKGROUND

The Ontario Breast Screening Program was expanded in 2011 to offer annual MRI and mammography to women with high-risk genetic mutations (e.g., BRCA1/2) and women with strong family histories and ≥25% estimated lifetime risk of breast cancer. Data to support high-risk screening is less clear in the nonmutation carrier group, as MRI has lower specificity among this population. The potential unintended consequences may be considerable and need to be explored. We aimed to describe the frequency of abnormal screens and biopsies.

METHODS

Demographic surveys and chart review consent were sent to a sample of 441 individuals enrolled in a high-risk screening program at two tertiary care hospitals in Toronto, Ontario. Retrospective cross-sectional chart review was undertaken for clinicopathologic data. The frequencies of abnormal screens and biopsies were calculated.

RESULTS

One hundred sixty-nine nonmutation carriers were included. The majority were white, employed, and highly educated. The median International Breast Cancer Intervention Study lifetime risk of breast cancer was 28.0% (range 24.5%-89.0%). 108 individuals (64%) experienced at least 1 abnormal screen and 13 (8%) had 3 or more over a median 3 years of screening (range 1-6 years). Of 55 biopsies, 3 (5.5%) were malignant. The cancer detection rate was 8.4/1000 screens (95% CI 3.2-22.4).

CONCLUSIONS

An MRI-based screening program for nonmutation carriers was effective at diagnosing breast cancer. However, this population experienced a high rate of abnormal screens and intervention. Further research is needed to improve the performance of MRI-based screening in these women.

Screening and Preventative Strategies for Patients at High Risk for Breast Cancer

PURPOSE

Current US guidelines recommend more intensive breast cancer screening and preventive strategies for patients at more than 20% lifetime risk for breast and ovarian cancer (high risk for breast and ovarian cancer [HRBOC]). Guidelines recommend that yearly mammograms alternating with magnetic resonance imaging (MRI) screening should be considered as early as 30 years old. Furthermore, BRCA mutation carriers should consider bilateral mastectomy and bilateral oophorectomy after age 35. It was unclear what the uptake of screening and risk-reducing strategies were for patients who were cancer-free and cancer survivors seen by Kaiser Permanente Mid-Atlantic States (KPMAS) Genetics.

METHODS

We retrospectively studied female patients (members of KPMAS between 2005 and 2016) diagnosed as HRBOC and/or tested for breast cancer-related mutations by KPMAS Genetics during 2013-2016. We identified cancer diagnoses, mammogram and breast MRI screening, mastectomies, and oophorectomies that occurred before and after the Genetics visit during the study period.

RESULTS

Our cohort included 813 women with a HRBOC diagnosis, with a median 51 years of age at diagnosis, 45% White, 38% Black, and 15% other ethnicity. Most cancers occurred prior to the Genetics visit: 513/527 breast cancer diagnoses and 55/57 ovarian cancer diagnoses. Fewer than five prophylactic mastectomies and 89 prophylactic oophorectomies were identified. Among 228 patients who were 30-75 years old, breast cancer-free at the time of HRBOC diagnosis, and members for over 6 months, 190 (83%) had at least one screening test (mammogram or MRI) after the consultation with Genetic, but 79% never had an MRI before or after the consultation.

CONCLUSION

Our findings suggest that earlier detection of patients with HRBOC and closer monitoring is needed.

Magnetic Resonance Imaging in Screening of Breast Cancer

Magnetic Resonance (MR) imaging is the most sensitive modality for breast cancer detection but is currently limited to screening women at high risk due to limited specificity and test accessibility. However, specificity of MR imaging improves with successive rounds of screening, and abbreviated approaches have the potential to increase access and decrease cost. There is growing evidence to support supplemental MR imaging in moderate-risk women, and current guidelines continue to evolve. Functional imaging has the potential to maximize survival benefit of screening. Leveraging MR imaging as a possible primary screening tool is therefore also being investigated in average-risk women.

Breast MRI screening for average-risk women: A monte carlo simulation cost-benefit analysis

BACKGROUND

Screening high-risk women for breast cancer with MRI is cost-effective, with increasing cost-effectiveness paralleling increasing risk. However, for average-risk women cost is considered a major limitation to mass screening with MRI.

PURPOSE

To perform a cost-benefit analysis of a simulated breast cancer screening program for average-risk women comparing MRI with mammography.

STUDY TYPE

Population simulation study.

POPULATION/SUBJECTS

Five million (M) hypothetical women undergoing breast cancer screening.

FIELD STRENGTH/SEQUENCE

Simulation based primarily on Kuhl et al⁸ study utilizing 1.5T MRI with an axial bilateral 2D multisection gradient-echo dynamic series (repetition time / echo time 250/4.6 msec; flip angle, 90°) with a full 512 × 512 acquisition matrix and a sensitivity encoding factor of two, performed prior to and four times after bolus injection of 0.1 mmol of gadobutrol per kg of body weight (Gadovist; Bayer, Germany). An axial T₂ -weighted fast spin-echo sequence with identical anatomic parameters was also included.

ASSESSMENT

A Monte Carlo simulation utilizing Medicare reimbursement rates to calculate input variable costs was developed to compare 5M women undergoing breast cancer screening with either triennial MRI or annual mammography, 2.5M in each group, over 30 years.

STATISTICAL TESTS

Expected recall rates, BI-RADS 3, BI-RADS 4/5 cases and cancer detection rates were determined from published literature with calculated aggregate costs including resultant diagnostic/follow-up imaging and biopsies.

RESULTS

Baseline screening of 2.5M women with breast MRI cost $1.6 billion (B), 3× higher than baseline mammography screening ($0.54B). With subsequent screening, MRI screening is more cost-effective than mammography screening in 24 years ($13.02B vs. $13.03B). MRI screening program costs are largely driven by cost per MRI exam ($549.71). A second simulation model was performed based on MRI Medicare reimbursement trends using a lower MRI cost ($400). This yielded a cost-effective benefit compared to mammography screening in less than 6 years ($3.41B vs. $3.65B), with over a 22% cost reduction relative to mammography screening in 12 years and reaching a 38% reduction in 30 years.

DATA CONCLUSION

Despite higher initial cost of a breast MRI screening program for average-risk women, there is ultimately a cost savings over time compared with mammography. This estimate is conservative given cost-benefit of additional/earlier breast cancers detected by breast MRI were not accounted for.

LEVEL OF EVIDENCE

3 Technical Efficacy Stage: 6 J. Magn. Reson. Imaging 2019.

Informing Women and Their Physicians about Recommendations for Adjunct Breast MRI Screening: A Cohort Study

It is unclear how best to communicate recommendations for breast cancer screening with MRI as an adjunct to mammography for women at high risk. This study compares the rates of breast MRI screening for two different methods of communication. The retrospective IRB-approved cohort study was conducted at Invision Sally Jobe Breast Centers (ISJBC). ISJBC provided Gail model risk assessment to all women presenting for screening mammography. Women with scores ≥ 19.6% were considered to be high risk. Over 2 years, ISJBC used two different methods to inform women at elevated lifetime risk and their physicians about recommendations for adjunct MRI screening (N = 561, mean age = 52 years, s.d. = 8.7). During Window A, information was sent to referring physicians as a part of the dictated imaging report, while later, in Window B, the information was sent to referring physicians as well as to the women themselves in a letter. Analyses were stratified by mammography screening frequency. One-time screeners presented in only Window A or Window B. Repeat screeners came both in Window A and in Window B. Breast MRI screening rates were significantly higher in Window B than in Window A (one-time screeners, N = 459, 9.8% vs. 14.4%, p = 0.047; repeat screeners, N = 102, 0% vs. 6.9%, p = 0.016). Although an observational study cannot assess causality, direct communication of risk-based recommendations for adjunct breast MRI screening to women and to their referring physicians was associated with an increased rate of screening breast MRI completion at the same clinic at which the women underwent mammography.

Screening Breast MRI Outcomes in Routine Clinical Practice: Comparison to BI-RADS Benchmarks

RATIONALE AND OBJECTIVES

The BI-RADS Atlas 5th Edition includes screening breast magnetic resonance imaging (MRI) outcome benchmarks. However, the metrics are from expert practices and clinical trials of women with hereditary breast cancer predispositions, and it is unknown if they are appropriate for routine practice. We evaluated screening breast MRI audit outcomes in routine practice across a spectrum of elevated risk patients.

MATERIALS AND METHODS

This Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study included all consecutive screening breast MRI examinations from July 1, 2010 to June 30, 2013. Examination indications were categorized as gene mutation carrier (GMC), personal history (PH) breast cancer, family history (FH) breast cancer, chest radiation, and atypia/lobular carcinoma in situ (LCIS). Outcomes were determined by pathology and/or ≥12 months clinical and/or imaging follow-up. We calculated abnormal interpretation rate (AIR), cancer detection rate (CDR), positive predictive value of recommendation for tissue diagnosis (PPV2) and biopsy performed (PPV3), and median size and percentage of node-negative invasive cancers.

RESULTS

Eight hundred and sixty examinations were performed in 566 patients with a mean age of 47 years. Indications were 367 of 860 (42.7%) FH, 365 of 860 (42.4%) PH, 106 of 860 (12.3%) GMC, 14 of 860 (1.6%) chest radiation, and 8 of 22 (0.9%) atypia/LCIS. The AIR was 134 of 860 (15.6%). Nineteen cancers were identified (13 invasive, 4 DCIS, two lymph nodes), resulting in CDR of 19 of 860 (22.1 per 1000), PPV2 of 19 of 88 (21.6%), and PPV3 of 19 of 80 (23.8%). Of 13 invasive breast cancers, median size was 10 mm, and 8 of 13 were node negative (61.5%).

CONCLUSIONS

Performance outcomes of screening breast MRI in routine clinical practice across a spectrum of elevated risk patients met the American College of Radiology Breast Imaging Reporting and Data System benchmarks, supporting broad application of these metrics. The indication of a personal history of treated breast cancer accounted for a large proportion (42%) of our screening examinations, with breast MRI performance in this population at least comparable to that of other screening indications.